The data from the recorders can be used to reconstruct the flight's final moments and determine the cause of the incident.

India would not allow a UN investigator to join a probe of a crashed Air India jet that some safety experts had criticized for delays in analysis of crucial black box data, two senior sources familiar with the matter told Reuters.

The Director General of AAIB is heading the probe. An aviation medicine expert and an Air Traffic Control officer have also been included in the investigation team.